Source

Purpose

This study was designed to examine the association between walking and future risk of dementia in older men.

Design

Prospective cohort study.

Setting and Participants

Distance walked per day was assessed from 1991 to 1993 in 2257 physically capable men aged 71 to 93 years in the Honolulu-Asia Aging Study. Follow-up for incident dementia was based on neurological assessment at 2 repeat examinations (1994-1996 and 1997-1999).

Main Outcome Measures

Overall dementia, Alzheimer disease, and vascular dementia.

Evidence

During the course of follow-up, 158 cases of dementia were identified (15.6/1000 person-years). After adjusting for age, men who walked the least (<0.25 mile/d) experienced a 1.8-fold excess risk of dementia compared with those who walked more than 2 mile/d (17.8 vs 10.3/1000 person-years; relative hazard [RH], 1.77; 95% confidence interval [CI], 1.04-3.01). Compared with men who walked the most (>2 mile/d), an excess risk of dementia was also observed in those who walked 0.25 to 1 mile/d (17.6 vs 10.3/1000 person-years; RH, 1.71; 95% CI, 1.02-2.86). These associations persisted after accounting for other factors, including the possibility that limited amounts of walking could be the result of a decline in physical function due to preclinical dementia.